Wrench and like hand tool



M ,6 A i g7, 1

' Y' 1932- T. 1.. FYFFE WRENCH AND LIKE HAND TOOL Filed June 50, 1931 Patented July 26, 1932 UNITED STATES PATENT OFFICE 'rnomas LILL'IE mrrrs'n, on DUN E; soo'rLANn, assIeNon '10 FYFFE & COMPANY LIMITED, on DUNDEE,- SCOTLAND, A BRITISH COMPANY wnnNon AND "LIKE HAND TOOL Application ar a .Tune so, 1931, Serial 110 541840, and in Great Britain August 23, 1930.

This invention relates to wrenches and like hand tools. The invention is concerned with tools of the type operating on the principle of the ratchet wrench, that is to say i, of the type in which a 'step-by-step rota tional movement can be imparted to the tool head by meansof oscillating movement of a handle; I i v The invention provides a tool of the above 'v type comprising the combination with a head and a handle portion, of a cam formed onor carried by 'the inner end of the handle, an arcuate bearing surface for the cam formed or carried by thehead and a linkage pivotally articulated at opposite ends respectively to the handle and the head, the arrangement being such that the handle may be swung about the adjacent end of the linkage to bring the cam into and outof engagement with. the co-operating bearing surface on the head and maybe moved bodily about the remote end of the linkage to bring the cam into juxtaposition with diflerent parts of the bearing surface.

It will be seen that according'to the invention the tool is of theratchetwrench type but the usual spring-pressed pawl is replaced by a cam fixed on or forming part of the inner end of the handle and the ratchet wheel is replaced by a cam-bearing surface formed on or carried by the head.

' By the elimination of the separate pawl and the ratchet teeth5'the tool embodying the invention can be manufactured more cheaply than the ordinary ratchet wrench and for the same reason itcan be very much stronger and less liable to be put out of order. At the same time the advantages of the ordinary ratchet wrench as regards facility of manipulation (e. giin screwing up a nut in an awk-' ward situation) are retained.

"Preferablyin carrying out the invention the cam-bearing surface is constituted by a plurality of grooves arranged side by side round a marginal portion of thehead which conforms to a circular arc struck from: the axis of the pivotal connection between the linkage and'the head, With this arrange- '6 ment the cam may be brought into co-ope'rating engagement with any one of the aforesaid grooves.

A further feature of this invention residesin providing the tool with a locking device which is operable at will to lock the handle to the head and so provide a rigid wrench or like tool when such is required.

The locking device referred to may conveniently comprise a wedge movable on the inner end of the handle (about the axis of the pivotal connection between the handle and the linkage) into such a position, between said end :and the cam bearing surface, as will'prevent swinging movement of the handle to disengage the cam.

One example embodying the invention will now be described with reference to the accompanying drawing in which Figure 1 is an elevation at the line 1-1 die 9 of the toolis at its inner endfscrewed into asocket member 10 with which is integrally formed a cam 11 for co-operation with the grooves 8 in the arcuate portion of the tool-head. The handle is articulated to the head by means of two links or straps 12 which at one end are pivotally connected to the head by a pin 13 and at the other" end are similarly connected by a pin 14 to the socket member 10. The connection between the linkage and the head is so located that the axis of the pivot pin 13 is coincident with the centre from which thearc of the grooved portion of the head .is struck;

The arrangement is such that when the handle. is in line with the links 12 the cam 11 will'be inengagement with one of the grooves 8 in the head, the engaged surfaces lying to one side of the centre line of the 8 and the handle will be free atobe rotated] into a position in which the cam is adjacent to another groove. It will be appreciated that swinging movementof the handle to disengage the cam takes place about the axis of the pivot pin 14 connecting the V linkage to the socket member on the handle,

while movement of the handle to bring the cam adjacent to another groove takes place .about the axis of the pivot pin 13 between the linkage and the head. It will also be appreciated that in manipulating the tool the latter is moved more or less like an ordinary ratchet wrench.

The wrench is provided with a .locking device of the following form so that when desired the handle may be locked :to the head to form a rigid tool like an ordinary solid cast wrencln The locking device comprises a wedge 15 mounted on a pin 16 extending between and carried by two arms 17 which are pivotally mounted on the inner end ofthe socket member 10 for movement about the pivot pin 14:. The wedge 15 isso positioned on the carrying arms 17 that when the cam is in engagement with a groove on one side of the centre line of .the linkage (as shown in Figure 1)., the wedge may be brought into engagement between the socket member and the adjacent cam groove which lies on the opposite side of the :aforesaid centre line. 'VVhen the wedge is so positioned (as shown in chain lines-in Figure 1) the socket member 10, head 5 .and

linkage 12 are all looked together and are movable as one. The wedge 15 is located at will in either an operative or inoperative position :by means of a pin (not shown) inserted through-an aperture 18 in the opposite .end of the wedge-carrying arm and entered in one of two co-operating apertures 19, 20 in the socket member.

Vithout departing from the invention, the construction described above may be modified considerably and it may be applied to tools of different forms, that is other than .a wrench.

I claim 1. A wrench comprising in combination a fiat head, at least a portion of the periphery of which correspondswith an arc of a .circle and is formed with .aseries of depressions, a handle, a link pivoted'at one end of the head at the centre of the arc, and at the other end to .the handle, .a projection, rigid with the handle and extending towards the head and to one side of the pivot of the handle, for engaging said depressions, a wedge, and a link pivoting said wedge to the end of the handle aforesaid, said wedge being movable into a position between the end of the handle and the head to lock the two together.

2. A wrench comprising in combination a head, a handle, a link pivoted at one end to the head, and at the other end to the handle, a single convex cam rigid with that end of the handle which isadjacent to the head, and a cooperating bearing surface formed on the head and consisting of a series of shallow curved recesses, the arrangement being such that the handle may be swung about the adjacent end of the linkage .to bring the cam into and out of engagement with the cooperating bearing surface of the head andmay bemoved bodily about the remote end of the linkage to bring the cam into juxtaposition with different recesses.

3. The combination with a wrench as claimed in claim 2, of a locking device operable at will to lock the handle to the head.

at. A wrench comprising in combination a .fiat head, at least a portion of the periphery of which corresponds with an arcof a circle and is formed with a series of depressions, a handle, a link pivoted at one end of the head at the centre of the arc and at the other end to the handle, a projection, rigid with the handle and extending towards the head and to one side of the pivot of the handle, for engaging said depressions, a wedge, and a link pivotingsaid wedge to the end of the handle aforesaid, said wedge being formed with its periphery curved to fit the depressions in the head, and being movable into and out of a position between theend of the handle and the head to lock the'two together.

v5. A wrenchIasCla-imed in claim 4 combined with a device for locking the wedge in its operative position.

' 6. A wrench comprising in combination a head, a handle, a link pivoted at one end to the head, and at the other end to the handle, acam-bearing surface comprising a series of shallow curved recesses formed contiguously on that end of the head adjacent to the link in an arc of a circlestruck from the center of the pivotal connection between the handle and the head, a cam which is rigid with that end of the handleadjacent to the link, isconstituted by a single convex projection, is

ans

movable, by pivotal movementof the handle,

inner end of the handle about the axis of the THOMAS LILLIE FYFFE. 

